If you think your bank is going to keep your bitcoins in some account then you can use your debit card to convert to dollars at the point of sale then you don't really understand the main revenue of banks.
Banks hold your dollars in their bank accounts. They then turn around and leverage your dollars in their account by 10 times to issue loans to people where they get their main revenue.
If people are holding their funds in bitcoins and only using banks as a transaction medium the bank is not making much money.
Don't expect banks to embrace Bitcoin. The reason they're all creating their own "blockchains" is so they can make it so that they can hold your funds and leverage it.
Every central bank warning about Bitcoin is another central bank realizing that they are going to lose if people start using Bitcoin.